Victorian Equal Opportunity and Human Rights Commissioner Kristen Hilton today said the anti-LGBTI posters found in Melbourne are a clear sign that a respectful debate will be difficult during a plebiscite or postal survey campaign on marriage equality.

"This is the type of hateful and inaccurate material that the LGBTI community warned would be publicised during any kind of plebiscite on marriage equality," Commissioner Hilton said.

"Loving couples have been waiting far too long for discrimination to be written out of our marriage laws and for marriage equality to be achieved in Australia.

"We must correct the record and call out false information, especially when it is unrelated to the actual postal survey that is set to ask solely whether two people of the same sex should be able to marry each other.

"Multiple reviews of the research in this area show that there is a broad consensus children with same-sex parents are no worse off than children with heterosexual parents."